Friday 24 October 2014

Toucan Tongues...and bill development

An almost embarrassing number of Collared Acararis; four ! have landed themselves in our nets in the past week of standard banding for Costa Rica Bird Observatory.  Our initial excitement has now dwindled to self-preserving musings of how best to extract and keep that snapping bill away from flesh at the same time.

We have been quite lucky to be able to closely examine a broad range of ages, from juveniles, almost surely straight out of the nest, to the beautiful adult below.

With such a run, it has been easy to observe the differences in bill development between the ages.  It is quite interesting to see and compare the development of structure, colour, and even strength, so up-close and personally. 

Adults also have far better bill-eye-hand coordination. 

Amidst requests to "take that thing off my finger, pleease" during processing, we have had many opportunities to see the amazing appendage-like tongue that is possessed by these creatures. 

Juveniles, likely not long fledged.  Note the dull colour of the bill and smoothness of the edge. 

And this feathery tongue!  Apparently used for helping push food down the throat, and loaded with taste receptors to decide whether its worth the effort or not.

This juvenile is developing bill serrations and colour, and that tongue is even more feathered.  Curving of the bill is becoming more pronounced.

The ultimate adult.  Strongly coloured bill.  Tongue is very feathered. 

Serrations are verified.

And this little guy.  Not caught in Tortuguero.  Didn't show his tongue. But Richard didn't want this to end on him being bitten. 
Emerald Toucanet, caught at Madre Selva, CRBO standard banding site in the Highlands.

~ Author Pauline Pearse (Richard's Aracari-bill opener when the bites hurt)

1 comment:

  1. That's what is called a serious bill.
    Cannot imagine for a moment that it would keep Richard quiet though.


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